Dual engine controls



Oct. 17, 1967 .J. c. MEDLEY' DUAL ENGINE CONTROLS Filed Oct. 19, 1965 8 Y E mv N TE R mm m VE WM M 0 $1 w w m 4/ m y J United States Patent Ofiflce 3,347,044 Patented Oct. 17, 1967 3,347,044 DUAL ENGINE CONTROLS Jackson C. Medley, East Peoria, 111., assignor to Caterpillar Tractor Co., Peoria, lll., a corporation of California Filed Oct. 19, 1965, Ser. No. 497,952 3 Claims. (Cl. 60-97) ABSTRACT OF THE DISCLOSURE Control of fuel supply to two remotely disposed engines from either one of two remotely disposed control stations.

In the earth-moving machine industry, there is a marked tendency towards handling much larger and heavier loads and this is often accomplished by coupling two large engine powered machines together and employing the power as well as the capacity of both. For reasons of economy, one man operates the machine through control means common to both. In some cases, it is desirable that both machines be operated from the usual control station of either.

For example, my assignee has developed a large trucklike vehicle for handling in excess of two hundred tons of earth, coal or other material. On many jobs such as working in a coal mine, it is unwieldy and time-consuming to turn such a machine at both ends of a short haul. Consequently, the machine is made with two large tractor units each supporting one end of a large body for carrying materials to be hauled. The tractor units face away from each other and resemble large rubber tired trucks, one of which is driven forwardly to pull the load while the other operates in reverse to push it. Both tractor units have cabs with more or less conventional appearing operators controls but which are arranged for complete control of both tractors from either cab.

The object of the pesent invention is to provide fuel supply controls for two remotely positioned engines including connections between the fuel controls of both engines so that the control of either will actuate the control of the other.

A further object of the invention is to provide controls which normally hold the two engines in a condition of low idle operation from which condition they may be accelerated and also to provide means to permit either or both engines to be shut down without interfering with subsequent normal operation of the control.

Further and more specific objects and advantages of the invention and the manner in which it is carried into practice are made apparent in the following specification, wherein reference is made to the accompanying drawing.

In the drawing:

FIG. 1 is a schematic view of the controls embodying the present invention showing the components which are disposed in two tractor cabs and the hydraulic lines interconnecting them; and

FIG. 2 is an enlarged sectional view in detail of a governor actuating cylinder which forms a part of the control system in each cab.

In the drawing, the engine and cab areas of two tractors are represented at and 10 and the engines have governor housings 11 and 11' with levers 12 and 12 for adjusting the governor setting and thus, the speed of the engine. A hydraulic cylinder for each engine generally indicated at 14 and 14 is pivotally secured to the engine as at 15 and 15' and these cylinders have pistons with rods 16 and 16 pivotally connected with the governor controlled levers. The operators station in each cab is provided with a foot throttle 17 and 17 adapted to open the valves 18 and 18' which are valves of conventional construction serving when closed to direct fluid from a suitable source of supply under pressure through lines 19 and 19' and return lines 20 and 20' back to the source. Upon being opened by depression of the foot peddles 17 or 17' either of the valves will direct fluid from the supply to both of the governor actuating cylinders.

The specific construction of the valves 18 and 18' is not shown as it is conventional and there are many valves capable of performing the same function. It will suffice to know, for an understanding of the present invention, that the valves contain spools for directing fluid in either of the paths mentioned and are urged to their closed position by an internal spring while they may be opened by depression of the foot peddle. Line 22 extending between the valves contains a shuttle valve 23 with a ball 24 actuated by pressure from either valve to close communication with the other and transmit pressure to a line 27 which is common to both of the cylinders 14 and 14'. The cylinder 14 is shown in FIG. 2 as having a spring 29 urging the rod 16 to a retracted position through a disc or washer 25 and a nut 26. Fluid under presure entering the cylinder 14 through the line 27 urges the piston rod to an extended position increasing the rate of fuel flow to the engine. It should be understood that the entire cylinder including the spring chamber is normally full of hydraulic fluid and the force of the pressure acting upon the rod is confined to an area which is the diameter of the rod itself. Consequently, only a small volume of hydraulic fluid is required to move the rod so that the use of accumulators such as shown at 28 and 28' in FIG. 1 is optional and dependent upon the character of the source of fluid under pressure.

Movement of the rod to increase the flow of fuel to the engine is limited by a tubular stop 30 which surrounds the rod and serves as an abutment for the washer 25. Movement in the other direction under influence of the spring 29 is limited by engagement of the Washer 25 with a shoulder 31 in the cylinder and this position of the rod represents the low idle position of the engine governor. A space 32 is provided within the cylinder to permit further retraction of the rod which is necessary when the governor control lever is moved either manually or by other means to an engine shut-down position.

The two hydraulic single acting spring return cylinders 14 and 14, serving as the actuating mechanism attached to the governor control levers, solves the problem of synchronizing both engines from either operators station. The return spring of each cylinder is reasonably accurately calibrated so that for a given extension a given force will be required to maintain the extended length. This is the force provided by hydraulic pressure acting on the piston rod of the cylinder. This pressure is, of course, controlled by the metering valves 18 and 18' which regulate pressure in the throttle cylinder hydraulic lines.

I claim:

1. Means for actuating the fuel feed controls of two engines from two remote positions comprising a fluid actuated motor operatively associated with the fuel feed control of each engine, a source of fluid under pressure, means communicating fluid from said source to both said motors, and two remotely positioned normally closed valves in said communicating means each operable upon opening to admit pressure to both motors.

2. The combination of claim 1 in which the communicating means includes a common line between the valves, a common line between the motors, and a shuttle valve in the first common line to direct pressure from either valve to the second common line.

3. In means for actuating an engine fuel feed control lever, a hydraulic cylinder having a piston connected with said lever, means to direct pressure to extend the piston and increase fuel feed, resilient means biasing the piston to a low idle fuel position, a stop at low idle position which includes a shoulder in the cylinder and a washer embracing the piston and engaging the shoulder but permitting movement of the piston beyond low idle to shut down position.

References Cited UNITED STATES PATENTS 2,404,545 7/1946 Stevens 3,214,901 11/1965 Iverson EDGAR W. GEOGHEGAN, Primary Examiner. 

1. MEANS FOR ACTUATING THE FUEL FEED CONTROLS OF TWO ENGINES FROM TWO REMOTE POSITIONS COMPRISING A FLUID ACTUATED MOTOR OPERATIVELY ASSOCIATED WITH THE FUEL FEED CONTROL OF EACH ENGINE, A SOURCE OF FLUID UNDER PRESSURE, MEANS COMMUNICATING FLUID FROM SAID SOURCE TO BOTH SAID MOTORS, AND TWO REMOTELY POSITIONED NORMALLY CLOSED VALVES IN SAID COMMNICATING MEANS EACH OPERABLE UPON OPENING TO ADMIT PRESSURE TO BOTH MOTORS. 